The burning sensation in the anus after diarrhea may be related to dietary factors, friction between stool and anus and other reasons. 1. Dietary factors: if you consume a lot of spicy and irritating foods such as chili peppers, because of the spicy red pigment can not be absorbed by the intestinal tract and mixed in the feces, when it is discharged from the anus in the process, it will lead to a burning sensation in the anus. 2. Friction between stool and anus: If the number of stool increases, it will lead to frequent friction between stool and anus, causing burning sensation in the anus. It is recommended that people with burning sensation in the anus after diarrhea should go to the hospital in a timely manner to clarify the cause, and if treatment is needed, it should be standardized under the guidance of the doctor, so as not to delay the condition of the body to bring adverse effects.